Cross head and piston rod and piston construction



Feb. 22, 1938. E. s. DENNISON 2,109,060

CROSS HEAD AND PISTON ROD AND PISTON CONSTRUCTION Filed Feb. 25, 1937 4 Sheets-Sheet 1 fig. 1.

law! ad/mu 4 Sheets-Sheet 2 E. S. DENNISON Filed Feb. 25, 1957 Feb. 22, 1938.

I/u/en for: Mam/d5. flea/3680a Feb. 22, 1938. E. s. DENNISON CROSS HEAD AND PISTON ROD AND PISTON CONSTRUCTION Filed Feb. 25; 1937 4 Sheets-Sheet 4 Fatented Feb.

PATENT OFFICE 1 C3085 HEAD AND PISTON BOD AND PISTON CONSTRUCTION Edward 8. Dennison, New London, Conn, auignor to Electric t Company, Groton, Conn, a

corporation of New Jersey Application February 25, 1937, Serial No. 127,670

13 Claims.

This invention relates to internal combustion engines, and has to do with a cross-head and piston rod and piston construction particularly suitable for use in two-cycle double acting iniection engines.

My invention is directed'to improved means for connecting the cross-head, to. the piston rod of an internal combustion engine and supplying cooling oil to the piston through the rod, while assuring adequate strengthoi the latter, the prevention of rocking or tilting of the pistonrod relative to the cross-head at its connection to the latter, ready accessibility for assembling and disassembling-the piston rod and the cross-head,

l5 and assuring that the oil passages of the crosshead are properly disposed relative to those of the piston rod in the assembling of these parts.

It is also an object 01' my invention to provide a Figure 2 is .a transverse vertical sectional view through the crank case and associated parts of 30 the engine of Figure 1, the piston rod and crosshead being sectioned substantially on the line 2--2 of Figure 5, and the upper portion of the connecting rodbeing shown in section, parts be-v ing broken away and certain parts being shown 35 in elevation;

Figure 3 is a sectional view taken substantially online3-3ofFigure4;

Figure 4 is a sectional view taken substantially on line 4--4 of Figure 3, parts being broken away 40 and shown in section in different planes for showing the oil passages, certain parts being shownin plan;

Figure 5 isa plan view, on an enlarged scale, of the cross-head and associated parts, the piston 45 rod being shown in transverse section, and the guide means for the cross-head shoe being shown fra'gmentarily and in section, certain parts being broken away;

Figure 6 is a sectional view taken substantial 50' on line 6-6 of Flgure 5; and

Figure 7 is a sectional view taken substantially on'li'ne 1'| of Figure 2.

The engine herein disclosed is, in general, similar in construction to the engine disclosed in my '55 copenjding applications, Serial .No. 114,568, for

, internal combustion engines.

able. In certain aspects, however, my invention may be applied to advantage to other types of I have illustrated my invention as applied to an engine comprising a crank case 0 of suitable construction within the lower portion of which the engine crank shaft (not shown) is mounted in a known manner. A cylinder I0 is suitably mounted in an entablature H supported by brackets, one oi which is shown at I2 in Figure 2, which bracketsare mounted upon U frames, one of which is shown at l3 in Figure 2, within the crank case 0. The brackets and the entablature 1 are suitably bolted to the U frame, and the cylinthe upper cylinder water-jacket. The upper end of cylinder I 9 is closed by a sectional water-cooled head 2| bolted to a thickened element or boss 22 at the upper end of the cylinder. An injection nozzle 23 is mounted in head 2i centrally thereof for injecting fuel into the cylinder.. The lower end of the cylinder is. closed by a head24bolted to a thickened element or boss at the lower end of the cylinder, said latter head also being sec- ;tional and water-cooled. Suitably disposed injection nozzles (not shown) are mounted in head 24 for injecting fuel into thejiower end of the cylinder substantially 'chordally thereof. The construction of the head 24 and the mounting of the injection nozzle associated therewith may be the same as in my above identified copending application for internal combustion engine, filed January '7, 1937, Serial No. 119,422. Head 24 has associated therewith a stuffing box 25 of known type, and a dome member 26 is appropriately mounted upon the top of crank case C and has associated therewith a stufling box 21 aligned with the stufling box 25. The engine so far described is similar in construction to that of my The cylinder is suitably water-jacketed,

two above identified copending applications, and need not be illustrated nor described in greater detail, it sufiicing to note that the engine may be of any desired construction suitable for the purposes intended.

A piston 33 operates in cylinder i3, and has associated therewith a piston rod 3| which operates through the stumng boxes 26 and 21. Rod-3| is provided with an axial bore 32 which is reduced in diameter at the lower end of the rod, as shown in Figure 2. A tube 33. of less exterior diameter than the interior diameter of bore 32, has a close sliding fit in the lower end oi. rod 3| and extends upwardly through bore 32, in concentric spaced relation thereto, to a short distance above the upper end of rod 3|. Tube 33 thus defines, with bore 32, an annular passage 34 for cooling oil, the upper end portion of this passage being flared upward at 34a. The tube 33 also defines an oil passage, and opens, at its lower end, through the lower end of rod 3|. The latter is also bored from its lower end to provide two supplemental passages 36 opening at their upper ends, by ports 36, into passage 34 adjacent the lower end thereof. The passage defined by tube 33 is an oil inlet passage, and the passage 34 is an outlet passage, suitable means to be later described being provided for supplying oil to the tube and for conducting oil away from the passage 34.

Piston rod 3| is provided, at its upper end, with a relatively thick outwardly projecting flange 33. The piston 33 comprises an upper head 39, a lower head 43, and a spacing member 4| disposed about rod 3| below and in contact with flange 33. Head 33 defines an interior central chamber 42 and a channel 43 extending about this chamber and separated therefrom by a wall 44 depending from top wall 46 of head 39. Wall 44, at the lower end of chamber 42, flts snugly about the upper end of rod 3 I, appropriately formed for that purpose as shown.

The lower end of channel 43 is closed by a flanged deflector 46 seating, in part, against the underface of head 39. The lower or base element of deflector 46 is clamped between the underiace of head 39 and web element 41a of a ring member 41 of angle cross-section, the upper end of which seats in a rabbet formed in the lower end of head 39. Ring member 41 is secured to head 39 by cap screws, one of which is shown at 43, passing through web 41a and screwing into head 39.

Deflector 46 fits snugly about the lower portion of wall 44, at the outer face thereof, and is provided, in its inner face, with a groove 49 which receives oil from chamber 42 through short passages or ducts 53 in wall 44. Above groove 49 the deflector 46 is decreased in thickness to provide a slight space 5| between the deflector and the outer face of wall 44, at the upper portion thereof, it being noted that the deflector is provided, at its upper end, with an outwardly projecting element 52 which extends along the roof of channel 43 in proximity thereto and towards the outer wall of this channel. Oil supplied to groove 49 from chamber 42 is thus caused to flow upward along the outer face of wall 44, then along the roof of channel 43, and thence downward along the outer wall of this channel, the latter being provided with appropriately located outlets, to be referred to more in detail presently. A spool member 64, disposed within chamber 42, is suitably secured upon the upper end of piston rod 3|, as by means of cap screws, one of which is shown at 66. Member 64 fits snugly about the upper end of tube 33. to which it is suitably secured as by welding, and serves to close the upper end of passage 34. At its upper end, spool member 64 is provided with a relatively thin flange 66- disposed adjacent the underiace of the center of;

top wall 46 of head 39. The outer portion of this flange is spaced a slight distance from an annular surface 61 provided on the underiaceoi wall 46 and disposed parallel to flange 63. The clearance between surface and flange 56 retards the escape of oil from above flange 66 sufliciently to assure that the space 63 above spool member I4 will be at all times maintained filled with oil, and positive flow of oil over the underface of wall 46, above flange 63, is assured. The oil entering space 63 from tube 33 flows outward from the latter along the underiace of wall 46, at the central portion-thereof, escapes between flange 66 and surface 61, flowing outward along the remainder of the roof of chamber 42, and then flows downward in chamber 42 along wall 44, escaping through the ducts 63 to groove 49 of the deflector 43. The central portion of top wall 46 of head 33 is efl'ectively cooled, thus eliminating danger of cracking or other injury to this wall due to overheating. The flow of the cooling oil along the inner and the outer faces of the depending wall 44 and the roof and the outer wall of channel 43 serves to cool the head 33, as a whole, in a highly eiflcient manner. This 011 flow, as well as the flow oi the oil in the chamber 42, is indicated by the arrows in Figure l.

The lower head43 defines an interior channel 63 extending about a hub 6| which fits snugly about piston rod 3| and is provided at its upper end with an outwardly projecting flange 62. A deflector 63, flanged at its upper end, closes the upper end of channel 63 and is clamped between the upper face of head 43 and a ring 64 of angle cross section, the lower end of which seats in a rabbet formed in head 43, web 64a of this ring being secured to head 43 by cap screws, one of which is shown at 65, these cap screws also passing through the flange of deflector 63, which is clamped between web 6411 and the upper end of head 43. Deflector 63 is provided with a depending portion 63a of approximately C shape in cross-section spaced away from the outer wall of channel 60 and extending inward along and a slight distance above the inner face of bottom wall 43a of head 43. The upper or base portion of deflector 63 is depressed and provided with an upwardly projecting rib 66 defining, with piston rod 3|, an annular depression in which flange 4|a, at the lower end of spacer 4| seats. This flange He is bolted to flange 62 of hub 6| of the lower head 43 by means of studs and cooperating nuts, one of these studs and its nut being shown at 61 and 63, respectively, it being noted that the stud also passes through the base or depressed portion of deflector 63. Spacer 4| is provided, at its upper end, with a flange 4| b which seats against the underface of flange 33 of piston rod 3| and issecured thereto by bolting studs and cooperating nuts, one of these studs and its nut being shown at 69 and 10, respectively. It will be noted that the stud 69 passes through the base element of deflector 46 which is thus clamped between flange 33 and wall 44 in the same manner as the base element of deflector 63 is clamped between flanges 4|a and 62.

Spacer 4| is provided with a plurality of lengthwise extending ribs 12, certain of these ribs bea ing each provided, a short distance'below flange 4|b, with an-outwardly projecting lug l8. hring u of .-r cross-section fits ti htly betweenthc rings 41 and 84, and is provided with suitably dis.- posed elements 'l4aseating between lugs I8 of ribs Handfiange 4"). This ring, which is split in a known manner, completes the sectional construction. of the piston, and it is provided with suitable openings for accommodating the nuts 10, as will be clear from Figure 1, it being noted that the ribs 12 of spacer 4| are suitably disposed to accommodate the nuts 88 of the bolting stud 81. While the piston 88 is preferably of the sectional construction shown and described, it may be of any other suitable construction, it being noted that each of the piston heads is provided with suitable grooves which receive piston rings, in a Port Tl opens into 'a groove 18 formed in the lower end of wall 44, extending from the outer face thereof and terminating short of the inner face of this wall. The outer end of groove I8 is in register with a port'l8 extending through the lower portion of deflector 48, which fits about wall 44. The lower end of passage 15 is in register with a port 88 through the base or web element of deflector 88, this port opening into a groove 8| in the upper face of flange 82, extending from the outer face of this flange and terminating short of the inner face thereof. The outer end of groove 8| is aligned with a port 82 in the portion of deflector 88 extending about flange 82. It will be clear that oil from channel 43 fiows therefrom downward through thepassages and ports shown and described, into channel between the outer'wall thereof and portion 83a of deflector 88. This oil .then flows along the bottom wall 48a of head 48 toward hub 8|, it being noted that the oil entering channel 80 is caused, by the deflector 88, including portion 83a thereof, to'flow downward along the outer. wall of channel 88.

Passage 15 of the right hand rib I2 shown in Figure 1 is in register, at its lower end, with a port 88 through the base or web element of the deflector 83. This-latter port 88 is in register with the upper end of an inclined duct 85 extending through flange 82 and opening, at its lower end, into channel 88 adjacent hub 8|, and between the latter and portion 88a of deflector 88. The upper end of passage I5 at the right hand of Figure'l is in register with the lower; end of a short duct 88 extending through flange 38 of piston rod 3|, and closed at its upper end by the base portion of deflector 48. Flange 38 is further provided with a duct 81 intersecting duct 86 and opening into the flared upper portion 84a of outlet passage 34. It will be understood that, in practice, certain of the ribs are provided with passages which permit downflow of the oil from channel 43 of head 38 to channel 80 of head 48, others of the ribs 12 defining, with the associated ducts, upflow passages for discharge of the oil from channel 80 to the outlet passage 34. The number of the downflow passages and the number of the upflow passages, as well as the cross area thereof, will depend upon the pressure,

rate of oil flow, and other factors, and may be y from and from the above description.

the oil from-the upper piston head to the lower piston head, and from the latter to the-outlet 84 of the piston rod 8|, is indicated by arrows in-Figure 1 andwill be clear The lower end of piston rod 8| is flat and normal to the axis thereof, and may have secured thereon, asby means of screws 88, a spacing ring 8| providedwith openings disposed to register with 'the lower end of tube 88 and the lower ends of theref a varied as desired to suit conditions. The flow of the supplemental outlet passages 88, as will be I clear from Figure "I. Portion 8|a of piston rod 8| fits snugly into a corresponding socket formed in the upper end of a cross-head 82, the bottom of this socket being fiat and normal; to the axis of the piston rod. Rod 8| is further provided, above portion 8|a, with an exteriorly threaded portion 8|b. A securing nut 88, comprising an upwar ly. tapering body 88a and. an outwardly projecting flange 88!) at the lower end of the body, screws upon portion 8") of the rod. .The

upper surface of flange 88b is convex and of sphericalcurvature about a center e located on the axis' of piston rod 8| and below the latter, as in-Flgure 2. A clamping member 85 is disposed about body 88a of nut 88 and is provided,

at its lower end, with a base curved conformably to and seating upon the upper face of flange 88b. Bolting studs 88, suitably anchored incross-head 82, pass through member 85 with Y suitable clearance 88a about each stud. Member which receives the upper end of'a key I80 secured by screws |8| in a groove in rod 8|, this key projecting into a keyway I82 opening into and ex-' tending from the upper end of the socket in crosshead 82. Key I88 serves-to assure proper positioning of portion 8|a of piston rod 8| in thesocket of cross-head 82, as will be explained more fully hereinafter, and also assures proper positioning of nut 88 upon portion 8") of piston rod 8|, while also holding this nut against turning movement. The annular plate 8| serves as a spacer for compensating for any slight inaccuracies in machining of the parts, it being understood that the thickness of this plate may be varied as required.

Forming the upper face of flange 88b of nut1i8 and the cooperating face of clamping member 85 in the manner stated, with provision for clearances between the studs. 88 and member 85 and between the latter member and the body 88a of the nut, in conjunction with the provision of the washers 81 and the spherical depressions about the studs 88, permits of slight movement of clamping member 85, relative to nut 83, about the center 0. This is advantageous in that it prevents or greatly reduces unequal tensioning of the studs 88 and also prevents subjecting the piston rod, at its connection to the cross-head 82, to objectionable transverse stresses. The lower end of rod 3|,"or

are maintained under compression at all times.

The. clamping member 95 is substantially square in plan, and of somewhat greater width t hanthe body of cross-head 92, the latter being provided, at its upper end, with lateral projections or flanges for reception of the studs 98, as will be clear from Figures 2 and 4. Since the studs 98 are spaced from the piston rod 3| a distance somewhat less than the width of flange 93b of. nut 93, this flange is suitably notched to accommodate studs 98, as in Figure 2.

Cross-head 92 is provided, at one side and adiacent its upper end, with a rectangular channel or groove of considerable width in which seats the inner portion of an elongated block I05 secured to the cross-head by cap screws I 08. Block- I05 is bored out from its ends to provide oil inlet and outlet passages I01 and I08, respectively, the inner ends of which are spaced apart and the outer ends of which are closed by screw plugs I09. The block I05 is provided with integral flanges -I I0, of circular outline, which abutthe ends of crosshead 92, the portions of the block extending outward-beyond flanges I I being of cylindrical shape and accurately finished to provide bearing sleeves II I. Each of these sleeves is provided with an opening II2 a short distance from its outer end,

this opening being of considerable extent circumferentially of the sleeve. Each sleeve II I receives thereon a sleeve I I3 at the upper end of a tubular link II4, conveniently formed integrally with the link. Sleeve H3 is confined between flange IIO and a washer I I5 through which passes screw plug I09, the latter being provided with'a head I09a which seats upon the outer face of washer II5. Link I I4 is pivoted, at its lower end, to a tubular link I I8, the lower end of the latter link being pivcted to a fitting I I1 suitably mounted within the crank case C. It will be understood that, in practice, there are two fittings II1, oil being supplied under pressure to one of such fittings and the other fitting constituting a return member through which the oil is returned to the source of supply. Linkage arrangements of this character for supplying cooling fluid to a piston are well known in the art and need not be illustrated or described'in greater detail. If desired, any other suitable known means, such as telescoping tubes, may be provided for supplying oil to passage I01 and delivering oil from passage I08. Sufllce it to state that suitable means is provided whereby cooling fluid, such as oil, is supplied to the passage I01 and delivered from the passage I08.

Block I05 and the cross-head 92 are bored to provide suitably disposed passageways for delivering oil to tube 33 and conducting oil from outlet passage. of, the piston rod 3|. Referring to Figures 2 and 5, block I05 is provided with an outlet port I20, adjacent the inner end of passage I01, which port is in register with the outer end of a horizontal passage I2I in the cross-head. Passage I2I intersects a vertical passage I22 in the cross-head, closed at its upper eudby a screw plug I23. Passage I22 opens,.at its lower end, into a short passage I24 extending lengthwise of cross-head 92 and opening into a passage I25 extending transversely of cross-head 92 and closed at its outer end by a screw plug I28. At its inner end passage I25 opens into a short vertical passage I21 which opens into the socket of cross head a: centrally or the man or the socket and is in register with-the central opening of plate 3|, which central opening is in register with the lower end of tube 33. In this manner, I provide a paseccentric openings in plate 9|, such openings be-- ing in register with the lower ends of the supplemental outlet passages 35. The latter passages, in eflfect, open directly into the upper ends of the passages M0. The latter passages open, at their lower ends, into inclined passages I3I bored in the cross head 92, and passages I 3| open, *at' their lower ends, into a passage I32 of greater diameter bored in the cross-head 92 from one end thereof and closed at such end by a screw plug F33. The outer end of each passage I 3i is closed by a screw plug I34, and passage I32 is intersected, adjacent its other end, by a vertical passage I35 of equal diameter bored from the upper end of cross-head 92 and closed, at its upper end, by a screw plug I38. A short passage I31 opens, at its inner end, into vertical passage I35, and is in register, at its outer end, with a port I38 opening through the inner wall of block I05 into passage I08 adjacent the inner end thereof. It will be seen that the outlet passage 34 of the piston rod 3| is thus connected to passage I08 of block I05 for conducting oil from the piston rod. In this manner oil is conducted to the piston through tube 33 and, after circulating through the piston heads and associated parts in the manner previously described, is conducted from the piston through passage 34 of the piston rod. It will be noted that the proper oil connections are assured by the act of assembling the cross-head and the piston rod, due to the provision of the key I00 and keyway I02 previously referred to.

propriately' formed to provide a bearing sleeve I40 which receives a wrist pin HI and associated bushings I42 and anti-friction bearings I 43, providing a pivotal connection between sleeve I40 and the upper end of a connecting rod I44, the lower end of which is connected, in a known manner, to the engine crank shaft. The connecting rod I44 and associated parts may be provided with suitable passages for supplying oil to the wrist pin bearings in a known manner.

A guide shoe I45, of known type, is suitably secured to the other side of cross-head 92, conveniently by bolting. This'shoe I45 operates in suitable guideways I48 of known typ appropriately mounted within the crank case C in a known manner. The cross-head guide shoe is of conventional type, as are the guideways and associated parts, and none of these parts need be illustrated ordescribed in greater detail. It is sufllcient to note that the crosshead has associated therewith suitable guide means, such as the guide shoe and the associated guides, referred to;

It will be noted that the greater portion of the cross section of the piston rod is available to transmit both tension and compression to laterally in the piston rod in a region subjected to tension during operation are objectionable and frequently cause failures of thepiston rod, such holes being-known as stress raisers. A further advantage of my constructionis that no attachments to the piston rod are necessary in eillecting the coolingoil connections, such connections being made automatically in assembling,

d, All operations g the piston rod the piston rod and the crossin assembling and disassemb and the cross-head are performed the upper. end of the latter, which is readily ible, this being conducive to expedition and facility in effecting the assembling and disassembling operations.

placement of the nuts, particularly the nuts 88,-

and of the cap screws I08.for securing the block- I 05, may be-"provided, as is well known in the art.

.WhatIclaimis: 3 I

1. In a double acting internal combustion engine, a cylinder, a piston operating therein and" provided with passages for circulation of cooling fluid, a cross-head having a socket in its upper' end, a piston rod operatively connecting said piston and said cross-head and seating in said socket with its lower end in sealing contact with the bottom of said socket, said piston rod'being provided with lengthwise inlet and outlet passages opening through its lower end and communicating with said piston passages, a securing member secured upon said piston rod adjacent and spaced from the upper end of said cross-head, said member being provided with an outwardly projecting flange having its upper face convex and of a spherical curvature, a clamping member having. its lower face curved conformably to and seating upon the upper face of said flange, said clamping member beingmovable'relative to said securing member about the common center of curvature of said surfaces, means securing said clamping member to and forcing it toward said cross-head efiective for maintaining the lower' end of said piston rod in sealing contact with the bottom of said socket, said cross-head having inlet and outlet passages opening through the bottom of said socket respectively in register with said piston'rod inlet and outletpassag'es, means for conducting cooling fluid to-and from said inlet and outlet passages of said cross-head, and a connecting rod operatively connected to said cross-head. 7 r

2. In a double acting internal combustion engine, a cylinder, a piston operating therein and provided with passages for circulation of cooling fluid, a cross-head having a socket in its upper end, a piston rod operatively connecting said piston and said cross-head and seatingin said socket, said piston rod having lengthwise inlet and outlet passages opening through its lower end and communicating with said piston passages, a nut' screwed upon said piston rod adjacent and spaced from the upper end of said crosshead, said nut comprising an upwardly tapering body and an outwardly projecting flange having .inlet and outlet .necting rod head.

its upper face ofconvex spherical curvature about a center on the axis of said piston rod, a

clamping 'memberihaving its lower face curved conformably to and seating. upon the upper face of saidflange, said member being spaced outwardly from the body'of saidnut, bolts securing saidlclamping member to and forcing it toward said cross-head effective for maintaining the lower end of said piston rod insealing contact with the bottom. of said socket, saidcross-head'having inlet and outlet passages opening through the bottom of said socket respectively in register with said piston rod inlet and outlet passages, means for conducting cooling fluid to and from said of said cross-head, and a connecting rod operatively connected-to "said cross head;

3. In a double acting internal combustion engine, a cylinder, a piston operating therein and provided with passages for circulation of cooling fluid, a cross-head having. a socket in its upper socket, said piston rod having lengthwise inlet and outlet passages opening through its lower end and communicating with said piston \passages, a nut screwed 'upon said piston rod adjacent and spaced from the upper end of said crosshead, a clamping member seating upon said nut, bolts securing said clamping member to and forcing it toward-said cross-head effective for maintaining the lower end of said piston rod in sealing contact with the bottom of said socket, said across- -head having inlet and outlet passages opening turning in said socket and also holding said nut against turning on said piston rod, means for conducting cooling fluid to and'from' said inlet and outlet passages of said cross-head, and a conoperatively connected to said cross- 4. In a double acting internal combustion en-' gine, a cylinder and a piston operating therein, a cross-head having a socket in its upper end, a piston rod operatively connected to said'piston and seating in said socket, a securing member secured upon said piston rod adjacent and spaced from the upper end of said cross-head, and-a clamping member seating upon said securing member and bolted to said cross-head, said members cooperating for securing said piston rod to said cross-head with its lower end in contact withthe bottomof said socket.

5. In a double acting internalcombustion engine, a cylinder and a piston operating therein, a

cross-head having a socket in its upper-end, a

I end, a piston rod operatively connecting said piston and said cross-head and, seating in said and seating in said socket, a securing member o0 secured upon said piston rod adjacent and spaced from the upper end of said cross-head, and a clamping member seating upon said securing member and bolted tosaid cross-head, said clamping member being capable of movement relative to said securing member about a center on the axis of and below said piston rod, said memberscooperating for securing said piston rod to said cross-head with its lowerend in contact with the bottom of said socket. I

6. In a double acting internal combustion engine, a cylinder and a piston operating therein, a cross-head having a socket in its upper end, a piston rod operatively connected to said piston .and seating in said socket, a nut screwed upon ly about the lower portion of the outer face of v said piston rod adjacent and spaced from the upper end of said cross-head, said nut comprising a body and an outwardly projecting flange having its upper face of spherical curvature about a center on the axis of and below said piston rod, a clamping member having a face curved conformably to and seating upon the upper face of said flange, said member being spaced from the body of said nut, and means securing said member to and forcing it toward said cross-head while permitting movement of said member relative to said nut about said center.

'7. In a piston and piston-rod assembly for double acting internal combustion engines, a piston, a tubular piston rod secured in said piston, an inlet tube secured in said rod in spaced relation to the inner face thereof and defining therewith an annular outlet passage, and a spool member fitting about the upper end of said tube and closing the upper end of said outlet passage, said spool member having at its upper end a flange in proximity to the under face of the top wall of the piston head, said piston being provided with interior intercommunicating spaces and passages leading from the upper end of said spool member to said outlet passage, the latter and said tube being respectively provided with outlet and inlet openings exterior of said piston.

8. In a piston and piston-rod assembly for double acting intemalcombustion engines, a piston, a tubular piston rod secured in said piston, an inlet tube secured in said rod in spaced relation to the inner face thereof and defining therewith an annular outlet passage, said piston comprising upper and lower heads and an intermediate member secured together and to said piston rod, said upper head defining a central chamber and a channel extending about said chamber and separated therefrom by a wall depending from the top wall of said upper head, a deflector closing the lower end of said channel fitting snugsaid depending'wall and extending upward therealong and along said top wall, said deflector having its upper portion spaced from said top wall and dependingwall and the latter having passages therethrough from said chamber to the space between said deflector and said depending wall, a spool member in saidochamber secured to the upper end of said piston rod fitting about the upper end of said tube and closing the upper end of said outlet passage, said spool member having at its upper end a flange in proximity to the underface of the top wall of said upper head, said lower head defining a hub and a channel extending thereabout, and a deflector closing the upper end of said channel fitting snugly about said hub and extending downward into the channel in spaced relation to the sides thereof with its lower portion extending along and spaced 9. short distance from the upper face of the bottom wall of said lower head, said heads and deflectors and said piston rod and intermediate member being provided with passages establishing com-.

munication between the channel of said upper head and the channel of said lower head at the outer side of said lower deflector and between the channel of said lower head at the inner side of said lower deflector and said outlet passage.

9. In a piston and piston-rod assembly 'for double acting internal combustion engines, a piston, a tubular piston rod secured in said piston, an inlet tube secured in said rod in spaced relation to the inner face thereof and defining therewith an annular outlet passage, said piston rod having an outwardiv extending flange at its upper end, said piston comprising upper and lower heads and a spacer secured together and to said flange, said upper head defining a central chamber and a channel extending about said chamber and sepward, a spool member in said chamber secured to said flange fitting about the upper end of said tube and closing the upper end of said outlet passage,

said spool member having at its upper end a flange disposed in proximity to the roof of said chamber, said lower head defining a hub and a channel extending therearound, said heads, flange, rod, and spacer having passages establishing communication between -the channels of said heads and between the channel of said lower head and said outlet passage, and deflector means fordirecting cooling fluid outward and downward in the channel of said lower head and then inward along the upper face of the bottom wall of said lower head to said hub.

10. In a piston and piston rod assembly for double acting internal combustion engines, a piston, a piston-rod secured in said piston and provided with inlet and outlet passages for cooling fluid, said piston comprising upper and lower heads, said upper head defining a central chamber and a channel extending around said chamber separated therefrom by a wall depending from the top wall of said head and provided with openings from the lower portion of said chamber into said channel, said lower head defining a hub and a channel extending therearound, said piston and rod having passages establishing communication between said channels and between said lower channel and said outlet passage, said inlet passage opening into said chamber, deflector means for directing cooling fluid along the roof of said chamber downward along said depending wall, then upward along the outer face of said depending wall, and thence along the roof and downward along the outer wall of the channel of said upper head,- and deflector means for directing cooling fluid downward along the outer wall of the channel of said lower head and then along the bottom wall of said lower head to said hub.

11. In a piston and piston rod assembly for double acting internal combustion engines, a piston,a piston rod secured in said piston and provided with inlet and outlet passages for cooling fluid, said piston comprising upper and lower heads each having an interior concentric channel, said upper head also having a central chamber communicating atits lower portion with the channel of said upper head, said piston rod having an inlet passage opening into said chamber and an outlet passage, said piston and rod having passages establishing communication between said channels and between the channel of said lower head and said outlet passage, deflector means for directing cooling fluid along the roof and downward along the surrounding wall of said chamber, then along the surrounding walls and the roof of the channel of said upper head, and deflector means for directing cooling fluid along the outer and the bottom walls of the channel of said lower head.

12. In a piston and piston rod assembly for double acting internal combustion engines, a pist'on, a, piston rod secured in said piston and provided with inlet and outlet passages for cooling fluid, said piston comprising upper and lower heads each having an interior concentric channel, said piston rod having an inlet passage communicating with the channel of said upper head and an outlet passage, said piston and rod having passages establishing communication between said channels and between the channel of said lower head and said outlet passage. deflector means for directing cooling fluid along the surrounding walls and the roof of the channel of said upper head, and deflector means for directing cooling fluid along the outer and the bottom walls of the channel of said lower head.-

13. In a double-acting internal combustion englue, 9. cylinder and a piston operating therein, a cross-head having a socket in its upper end, a piston rod operatively connected to said piston and seating in said socket; a seeming member secured upon said piston rod adjacent and spaced from the upper end of 7 said cross-head, and bolting means attaching said securing member to said cross-head, said members cooperating for securing said piston rod to said cross-head with its lower end in contact with the bottom of said socket.

EDWARD S. DENNISON. 

